Wing lift modification



A. GOUGE WING LIFT MODIFICATION July 30, 1946.

Filed June 16, 1943 7 Sheets-Sheet 1 July 30, 19460 A. GOUGE WING LIFT MODIFICATION Filed June 16, 1943 7 Sheets-Sheet 2 July 30, 1946. A. GOUGE WING LIFT MODIFICATION 7 Sheets-Sheet 3 Filed June 16, 1945 July 30, 1946. A. GOUGE WING LIFT MODIFICATION Filed June 15, 1945 7 Sheets-Sheet 4 July 30, 1946. A. GOUGE 2,404,956

WING LIFT MODIFICATION Filed June 16, 1943 7 Sheets-Sheet 5 July 30, 1946. A, GOUGE 2,404,956

WING LIFT MODIFICATION Filed June 16, 1943 7 Sheets-Sheet 6 Fig 14.

July 30, 1946. A. @0116: 2,404,956

WING LIFT MODIFICATION Filed June 16, 1943 '7 Sheets-Sheet 7 Patented July 30, 1946 WING LIFT MODIFICATION Arthur Gouge, Rochester, England, assignor to Short Brothers (Rochester & Redford) Limited,

Rochester, England Application June 16, 1943, Serial No. 491,083 In Great Britain November 3, 1942 Claims.

This invention relates to wings for aircraft in which a trailing portion is separated from the main portion so that it may be extended rearwardl to enable the aerodynamic characteristics of th wing to be altered during flight. In an earlier British Patent No. 443,516, January '7, 1935, the specification described a controlling section which is housed in the trailing portion of the wing and which can be extended rearwardly by running on circular tracks carried in the main wing structure and in which the extended section, which ha since become known as the Gouge flap, has been caused to extend the wing surface with the upper portion of the flap in a continuous curve with the upper portion of the main wing.

The object of this invention is to improve the high lifting qualities of the aircraft, both i or takeoff when additional lift is required without undue increase in drag, and fo landing when still further increase in lift is desired at the expense of increase in drag, which latter however is then beneficial, by causing reduction in speed and consequent reduction in the distance of travel when bringing the aircraft to rest.

One form of construction in accordance with this invention comprises a main or primary flap which is mounted on runners in the trailing portion of the main wing, in such a manner that when this Primary flap is moved rearwardly it extends the wing at the same time opening a slot between its forward portion and the rearward portion of the main wing. Below this primary flap a secondary flap is mounted on runners contained in the primary flap, and the said secondary flap is also in such a, form that when it is moved rearwardly a slot is opened between its upper forward surface and the lower rearward surface of the primary flap.

The mechanism for operating the primar flap and the secondary flap may be such, that the commencement of the movement moves the secondary flap rearwardly until it has extended its full travel and has opened the slot between itself and the primary flap, and then the primar flap is picked up by the mechanism and moved rearwardly so as to still further extend the double flap until the forward portion of the primary flap is separated from the trailing portion of the main wing so as to leave a slot between the primary flap and the wing. Both slots are formed so as to form a rearwardly directed channel the entrance of which is in advance on the under side of the wing, and the exit of which is on the upper portion, so that the flow of air through the slots from the under side to the upper side of the wing merges with the airstream flowing over the wing surface and prevents turbulence which would otherwise arise.

It is desirable to open one slot only when the aircraft is taking off, and to open both slots when approaching to land. When both slots are opened the primary and secondary flaps are both extended to the position where maximum drag and maximum lift are obtained. When one slot only is opened the lift is increased without excessive increase in drag and this opening of one slot only is the best adjustment for taking off. This separate setting of the flaps for take-off and for landing, requires the movements of the flaps to be divided into first and second stages, with some means for holding one of the flaps in order to prevent the opening of the slots simultaneously.

The taking off position for the flaps may be secured either by extending the secondar flap only while the primar flap is held securely to the wing, or by extending the primar flap while the secondary flap is held securely to the primary flap. The landing position for the flaps is secured by fully extending both flaps, either by extending the primary flap when th secondary flap has completed its adjustment, when the secondary flap is carried outwards with the primary flap and may have additional angular adjustment imparted to it during the extension of the primary flap, or in the case of the primary flap being extended first, the secondar flap remains closed against the trailing surface of the primary flap, until the latter has completed its outward adjustment when it separates and opens the slot between the two flaps.

In order that this invention may be clearly understood reference is made to the accompanying drawings, in which Fig. 1 is a diagrammatic section of a wing to which primar and secondary flaps are fitted, and in which the primary flap with the secondary flap held to it is ready to be moved outwards simultaneously, the secondary flap not being extended until after the primary flap has completed its rearward movement; Fig. 2 is the section showing the first movement with the secondary flap still in contact with the primary flap; and Fig. 3 is a similar cross section with the secondary flap extended. Fig. 4 is a section of a modified form of wing in which the primary flap and secondary flap are shown in the closed position, and Fig. 5 which corresponds to Fig. 2, shows this modification after the first movement when the secondary flap is extended rearwardly, so as to open a slot between itself and the rear under portion of the primar flap. Fig.

6 shows the same mechanism in the second position, in which the secondary flap remains extended, while it is carried further rearwardl and downwardly by the extension rearwardly of the primar flap. Fig. '7 is the section of another arrangement of mechanism for moving the primary flap and secondary flap, both flap being in the housed position. Fig. 8 is a similar view of the mechanism shown in Fig. 7, but with the secondary flap extended, and Fig. 9 is a similar view with both primary and secondary flaps extended.

Fig. 10 is a plan of details of mechanism for controlling the flaps when moved in their required sequence. Fig. 11 is a section taken on the line XI-XI in Fig. 10, and Fig. 12 is a view similar to Fig. 11 showing the parts in different positions. Figs. 13, 14 and 15 are diagrammatic views similar to Figs. 4, 5 and 6 of another operating mechanism, and Fig. 16 is a view similar to Fig 2 of yet another operating mechanism.

Similar letters of reference apply to like parts in all the figures. A is the main wing; B is the primary flap; C is the secondary flap; D is a screwed shaft, which is rotated by suitable means not illustrated in the drawings and is for the purpose of driving a nut D for movin the primary flap B and secondary flap C as required.

Referring particularly to Figs. 1, 2 and 3, the screw shaft D engages with the nut D connected to the cross bar D in the primary flap B, in such a manne that when the screw shaft D rotates it presses against the crossbar D and moves the primary flap B outwardly upon its guiding rails not shown in the drawings. This movement carries with the primary flap B, the secondary flap C. Pivoted in the primary flap B, is a bell crank lever 13 one arm of which carries a link B having a pin B on its end, runnin in a slot A in the main wing A. When the primary flap B has arrived at the position shown in Fig. 2, the pin B on the slot A has arrived at the rearward end of the slot where it is arrested, and then the continued rotation of the shaft D, continuing to move the primary flap B in a rearward direction, causes the bell crank lever B to rock and thrust rearward a link B which is connected to an arm C which, through a connectin link C pushes rearwardly a bracket C3 carried on the secondary flap C, thus causing the secondary flap C to move rearwardly and to open a slot between its upper surface and the undersurface of the primary flap B. The bell crank lever B is locked to prevent its rocking during the initial movement of the primary flap B, by a spring-pressed latch B the spring of 5 which is not shown. When however the initial movement of the primary flap is completed, the screwed shaft D has been moved about its end mounting into a position in which it pushes aside the latch B and so allows the bell crank to rock. The continued travel of the nut not only extends the secondary flap C to the position shown in Fig. 3, but it also carries the primary flap further backwards so as to increase the amount of opening of the slot between the primary flap B and the main wing A.

On reversing the direction of rotation of the screw shaft D, the primary flap B commences its forward closing movement and carries with it an arm C which, through its connecting link C and the bracket C returns the secondary flap C to its forward closed position. When this position has been arrived at, the bell crank lever B which has been moved by the link B connected to the arm C rocks into engagement with the latch B thus anchoring the bell crank lever B in the position shown in Figs. 1 and 2. The continued rotation of the screw shaft D now advances the primary flap and secondary flap forward together being permitted to do so by the pin B on the end of the link 13 travelling freely in the slot A in the main wing A.

Figs. 4, 5 and 6 illustrate a slightly modified construction where the screw shaft D is caused first to move the secondary flap C to an extended position and then by picking up the primary flap B, and move it rearwardly to further extend the secondary flap 0 and to open a slot between the forward upper portion of the primary flap B and the rearward portion of the main win A.

In this arrangement the nut D is pivoted in guides l3 and is not connected to the cross bar D but thrusts against it to extend the primary flap B only after it has travelled some initial distance along the screwed shaft D, which initial movement serves to extend the secondary flap C by way of the link C connecting the nut D to the secondary flap. During this initial movement, the primary flap B is locked to the main wing A by a latch B An extension on the nut D presses this latch aside and so frees the primary flap to move rearwardly when the secondary flap has been fully extended as shown in Fig. 5. To prevent the primary flap B from uncontrolled movement rearwardly as might otherwise take place when it is unlocked from the main wing A, a nut 13 is provided on the shaft D. This nut D is mounted to rotate freely in a housing supported in guides B carried on the primary flap.

In Figs. 7, 8 and 9 a slightly modified construction is shown in which the secondary flap C is first separated from the primary flap B by means of a connecting link C which is jointed at C to a forward extension C which is connected to the nut D travelling on the screw shaft D. In this construction the rotation of the screw shaft D carries the link C C 0 rearwardly, thus extending the secondary flap G into the position shown at Fig. 8. In this position the rear end of the forward part C of the link bears against a thrust block B on the primary flap and the rollers C carried on the pin of the joint C engage in recesses of the half-pinions E which are mounted for rotation in the primary flap B and are urged by springs, not shown, in a clockwise direction as viewed in Fig. 11. The teeth of these half-pinions engage with toothed rack A fixed to the main wing A. Thus, as the link 0 C C is moved rearwardly by continued rotation of the screw shaft D, the primary flap is extended under the control of the half-pinions, which roll along the racks A until the primary flap has reached its limiting position, when the half-pinions have turned over into the position shown in Fig. 12.

When the direction of rotation of the shaft D is reversed to retract the flaps, the rollers C move to the left, as seen in Fig. 12, taking with them the half-pinions B and consequently the primary flap, until the position shown in Figs. 8 and 11 is attained. The rollers C are now free to disengage from the recesses in the halfpinions, so that continued movement of the link C C C retracts the secondary flap C leaving the half -pinions in the primary flap B.

Figs. 13, 14 and 15 illustrate a similar construction of main wing A, primary flap B and secondary flap C in the three positions as previously illustrated in respect to the constructions shown in Figs. 4, 5 and 6 with the difference that in these new figures the means for operating the flaps does not contain any positive locking arrangement. The secondary flap C in this arrangement is illustrated as extending first from the primary flap 13 while the latter is held by means of a spring E which continually tends to draw the primary flap B up against the recess in the wing A. The effect of this is therefore to cause the nut D on the screw shaft D to begin its rearward movement by first pressing out the secondary fiap C to the open position and then by continued movement to press out the primary flap B to the extended position. A gate mechanism may be applied to limit the number of turns of the screw shaft so as to stop the outward movement of th nut D when the slot in front of the secondary flap C has been opened. A second position on the gate enables the screw shaft to be driven to carry the nut D beyond to the position where both the flaps B and C are extended with slots open in front of them in the position best suited for effecting a landing.

Figure 16 illustrates a somewhat similar mechanism in which the primary flap B is moved backwards while the secondary flap C is held against it by a spring E In this construction the primary flap B would complete its rearward movement and then the secondary flap C would be moved out against the pressure of its spring E Although this invention describes a main flap and a secondary flap only, further flaps may be provided each running on guides on the flaps immediately in front, all of which would move step by step in their turn.

Multiple flaps as described enable the cross-section profile of the fiapped wing to be retained in a reasonably continuous form giving less abrupt change in contour in the extended positions. The circular tracks on which the Various flaps run may be eccentric to the under surfaces against which the flaps are housed, or they may be concentric, in which case the upper surfaces of the flaps would be shaped to provide the necessary form of slot when the sections are extended rear- Wardly.

What I claim as my invention and desire to secure by Letters Patent is: v

1. The combination with an aircraft wing, of a trailing edge flap, which is normally partially housed in a recess in the undersurface of the wing with its lower surface in alignment with the lower surface of the wing but is extensible rearwardly and downwardly from said recess, said flap being formed of separable front and rear sections whereof the rear section is normally partially housed in a recess in the undersurface of the front section, and a common actuating mechanism for operating in sequence on the two sections of the flap to extend the flap into extended positions in all of which the upper surfaces of said sections form with the upper surface of the wing a substantially continuous curved surface which, apart from the slots, is unbroken and devoid of sudden discontinuities, initial movement of said actuating mechanism being effective to extend the rear section only to open a first slot between the same and the front section, and continued movement of said actuating mechanism being effective to extend both said sections, to open a second slot between the front section and the trailing edge of the wing.

2. Apparatus as claimed in claim 1, comprising a lock for latching the front section of the flap to the wing during the initial extension of the rear section to open the first slot, and a release device for automatically releasing said look on completion of said initial extension.

3. Apparatus as claimed in claim 1, comprising a spring for preventing extension of the front section of the flap during the initial extension of the rear sections to open the first slot, and means associated with the actuating mechanism for overpowering said spring on completion of said initial extension.

4. Apparatus as claimed in claim 1, comprising a rotatable screwed rod mounted in the wing, a nut mounted on the rod and constrained to travel axially thereon as the rod is rotated, a linkconmeeting the nut and the rear section of the flap, and an abutment on the front section of the fiap arranged to be engaged and moved by the nut on completion of the initial extension of the rear section of the flap by said link.

5. Apparatus as claimed in claim 1, comprising a rotatable screwed rod mounted in the wing, a nut mounted on the rod and constrained to travel axially thereon as the rod is rotated, a link connecting the nut and the rear section of the flap, and a latch securing the front section of the flap to the wing, the nut cooperating with the latch to release it on completion of said initial extension of the rear section of the flap.

ARTHUR GOUGE. 

